SHORT COMMUNICATION: ACCELERATED PUBLICATION: Dye solar cells without electrolyte or hole‐transport layers: a feasibility study of a concept based on direct regeneration of the dye by metallic conductors

Flat structures consisting of dense dye‐sensitized TiO2 films with various materials for dye regeneration (TiO2/dye/regeneration material) are compared. Au and PEDOT:PSS were tested as metal or metal‐like regeneration materials and compared with reference compounds, such as the redox couple I−/I in solution and p‐type CuSCN. Under the exclusion of TiO2 bandgap excitation, the short‐circuit photocurrent densities for the various structures differ by less than ∼30%, suggesting comparable charge separation efficiencies. The good performance of a metallic regeneration material implies, that the frequently assumed requirement of p‐type or ‘hole conducting’ properties for the regeneration material in solid state dye solar cells is questionable.